The latter rule works perfectly fine, but the former gives me this weird behavior when opening vim. After manually going back into normal mode, both mappings work as expected (changing the tabs).

What gives? Am I missing something simple here?

Btw, I'm using CLI vim (i.e., not MacVim) on OSX 10.5 via iTerm2. I've already combed through my entire .vimrc file and installed plugins and confirmed--even with all plugins disabled and all other options commented out--I get this behavior because of the line above.